Æthelstan of England

Aethelstan of England (893-27 October 939) was the first King of England, reigning from 927 to 939, preceding Edmund I of England. He was the last king of Wessex, reigning from 924 to 927 and succeeded Edward the Elder.

Biography
Aethelstan was born in 893 to the House of Wessex, a Christian dynasty of Anglo-Saxons. He succeeded his father Edward the Elder as king of Wessex on his death in 924, as within weaks of his father's death his brother Aelfweard of Wessex (who was briefly crowned king of Wessex, but not Mercia) died. Aethelstan conquered Jorvik in 927, and with the Vikings pushed out of England, he proclaimed himself "King of England", its first united ruler. In 934 he forced King Constantine II of Scotland to submit to him after an invasion, but in 937 the Scots and Vikings invaded England. At the Battle of Brunanburh, he defeated their armies, but he died in 939, letting the Vikings retake York.